Scratching at left ear

I notice tonight that Karma was scratching at her left ear and shaking her head ALOT. I just looked at both her ears, with a bit of a struggle . The right ear looks to be clean. nice and pink nothing wrong at all. The left ear has a lot of black stuff in it. It looks like it is spray painted black on the inside, I mean a pointelism look. If is just dirty? If she has ear mites what does it look like? Would it be in both ears of just one? How do I clean her ear? Is this something that needs a vet or is her ear just dirty and needs to be cleaned? My DH says she has not really been doing it while I am at work, its just every once and a while. Could it just be wax build up? She has no pain when I touch her ears. She just does not like me looking in them but she still loves to have my scratch them.

What should I do?

Get a couple q tips, then get her comfy snuggly in your lap, petting her, rub her ears, head, turn her ears in side out playfully.... the gizmo look.....Gently clean her ear with q tip, pushing q tip upward, not down into ear. Black gunk in the ear can be build up, or a sign of infection from ear mites or other.....Ear mites are microscopic so you can't see them, but if she is extremely sensitive on that side compared to the other, definitely a vet visit!

She does not seem to be any more sensitive on that side than the other. It just looks dirty to me. Sohuld I use anything like alchohol or should the qtip be dry. If it is an infection should I look for anything like redness or any other signs? I will take her to the vet if need be but if the ear is just dirty I don't want to put her through that kind of drama. She hates having her temp taken. You know something weird up her butt

There's no reason for one ear to be normal and the other to be very dirty, aside from a possible infection or earmites. If it were just a little it could be wax, but that's shouldn't be very thick or dark. It's obviously bothering her if she's scratching/digging at it.
Best to schedule a vet visit. Hopefully your vet isn't like the one I used to have, every time I had them check Sho's ears they'd say it was just "some dirt from outside".... he's a house cat.

No alcohol! Just clean q tip gently...... Once you clean it, check q tips and ear. Maia had a problem with one ear doing this exact thing though she had a little scaby spots and I took her to the vet. No mites, no infection, some irritation he said that was clearing up already. It came back a couple weeks later, so I clean them once a week, she loves it! Now her ears are beautiful!

uno had it when he was young, the same symptoms. it was ear mites and infection. take your cat to the vet, they will give you some liquid.
when you have applied it let your cat shake his head so the medication can spread evenly.
good luck mostlikely its nothing serious